Typewriting machine



1933- R. e. THOMPSON TYPEWRITING MACHINE Filed June 15. 1951 xg/gi .v VV MA t w lllllllllillllllllll'lHi B ENTOR RUSS L THOMPSON ATTORNEY Patented Nov. 7, 1933 entree s'rATEs 1,934,338 TYPlEWl-tlTIN G MACHINE Russell G. Thompson, Rochester, N. Y., assignor to Elcctromatic Typewriters, Inc, New N, Y., a corporation of New York York,

Application June 15, 1931. Serial No. 544,344

1 Claim.

This invention relates to typewriting machines, and particularly to power operated typewriting machines in which certain of the numeral keys are operatively connected with a totalizer in a well known manner for bookkeeping purposes. In machines of this kind, the type bars are actuated by means of cams which are selectively engaged with a power driven roller having a resilient surface of relatively soft material. In the operation of such a machine, it frequently happens that when the numeral type bar and totalizer are simultaneously operated, the cam slips on the power driven roller and digs into its surface without actuating the type bar to print or the totalizer.

The principal object of this invention is to provide simple, inexpensive and eiilcient means whereby the cams which simultaneously operate numeral type bars and the totalizer are positively engaged and driven by the power driven roller.

Another object of the invention is the provision of a power driven roller in a machine of this kind having bands of hardened material for actuating those cams which carry the heavier load, thus protecting the roller against injury by those cams.

Still another object of the invention is the provision of a power driven roller in a machine of this kind having bands of rigid hardened material provided with means for positively engaging and driving those cams which carry the heavier load, thus overcoming any liability of slipping, resulting in a failure to operate the machine when the cams engage a yielding surface such as heretofore employed.

To these and other ends, the invention consists in the construction and arrangement of parts that will appear from the following description when read in conjunction with the accompanying drawing, the novel features being pointed out in the claim at the end of the specification. I

In the drawing:

Fig. l is a fragmentary transverse section of a power operated typewriting machine equipped with a totalizer and illustrating one possible embodiment of the invention;

Fig. 2 is a front elevation, partly in section, of

' I the power driven roller, part being broken away to conserve space, and

Fig. 3 is a transverse section of the power driven roller showing one of the usual letter printing cams associated therewith.

Referring particularly to the drawing, in which like reference numerals refer to the same part in all views, 1 is a platen, and a type bar 2 is pivotally mounted at 3 on a fixed part and has types 4 and 5 at or adjacent its free end which engage the platen or a work sheet thereon to print. A toggle lever B is pivoted to the. type bar and connected with a power actuated bell crank lever l by means of a link 8 whereby the type bar is actuated into engagementwith the platen. A spring 9 connects the lever 7 'with 5 a fixed part and resiliently retains the parts in the normal position, with the type bar in the retracted position. The bell crank 7 is actuated by power driven devices selectively controlled by the usual keys and comprising a bell crank 11 7Q pivoted on a fixed part and having an arm projecting downwardly and provided with a cam 12 arranged adjacent the face of a power driven roller 13, the other arm of said bell crank being connected with an arm of the lever 7 by means 7 of a link 14. A spring-pressed arm 15 tends to turn the cam 12 into engagement with the power driven roller or a stop 16 on a key actuated lever 17 also pivoted on the bell crank 11 and operatively connected with a key lever 18 having a key 19 whereby it may be manually operated against the tension of a spring 21. The parts thus far described are or may be of usual or well known construction, and further detailed description thereof is deemed unnecessary here.

It will be understood that a plurality of the type bars 2 are provided as usual, certain of which are provided with types for printing numbers, and in a bookkeeping machine such type bars are operatively connected with a totalizer 22 of usual or well known construction, so that the totalizer will be actuated each time one of the numeral keys is depressed. To this end, the totalizer shaft has a ratchet 23 fixed thereon which is engaged by a spring-pressed pawl 24 pivoted on an arm 25 loosely pivoted on the totalizer shaft. A link 26 connects the arm 25 with an arm of the bell crank lever 7. By this arrangement, it will be noted that the totalizer is operatively connected with the key controlled or power actuated devices so that each time a numeral key is actuated to print a number, the lever 7 is actuated to operate thetype bar and simultaneously actuates the totalizer to record the number printed.

In machines of this type, in which the power roller is constructed of resilient material such as rubber, having a relatively soft surface with which the cams having knurled or milled engaging surfaces cooperate, when an overload is put 110 on the cam, as when it operates the type bar and totalizer simultaneously, it has a tendency to slip and dig into the surface of the roller, thus destroying its surface and failing to operate. It is the purpose of the present invention to provide a power roller with hardened or rigid zones or rings for driving those cams which are subject to an overload such as operating the totalizer, but retaining the usual resilient construction between said zones for driving other cams, thus retaining the substantially noiseless operation thereof. To this end, the power roller 13 is provided with bands 31 arranged in position thereon to be engaged by the cams 12 which operate numeral type bars and the totalizer simultaneously, or other overload. The bands 31 are constructed of relatively hard, rigid or non-resilient material which may be metal, such as iron or the like. The bands or rings 31 have their outer surfaces knurled, or they may be provided with fine serrations corresponding to similar serrations on the facesof the cams which co operate therewith. t will be noted that by this arrangement, the bands are positively engaged r by the cams and there is no liability of yielding or relativeslipping, resulting in fouling or injury to the parts. The powerdri'ven roller cornprises a core 32 which is frictionally engaged by the bands 31 as by a driving fit in properly spaced relation, and the intermediate resilient or rubber bands 33 are thereafter molded or stretched on the core between the bands 31.

Although only one embodiment of the invention is shown and described herein, it will be understood that this application is intended to cover such changes or modifications as come within the spirit of the invention or scope of the following claim.

I claim:

In power driven typewriting machine, the combination of a platen, a plurality of type bars adapted to cooperate with said platen, certain of said type bars having letter characters thereon and certain others having numeral characters thereon, a single power driven roller for actuating all of said type bars and comprising bands of soft material and bands of hard mateterial adjacent thereto and having serrations on their surfaces, cams arranged to cooperate with said bands of soft material to operate the types having letter characters thereon, a totalizer, means connecting said totaliz-er with said type bars ha 'ing numeral characters thereon for simultaneous operation therewith, cains to cooperate with said bands of hard mate-a1 for simultaneously operating said last mentioned type bars and totalizer, and means for selectively operating said cams.

RUSSELL THOMPSON. 

